IV CONTENTS. 



Page 

 XII. Note on the Chief Theorem of Lie's Theory of Continuous 



Groups. By Stephen Elmek Slocum 237 



XIII. A Rerixion of the Atomic Weight of Iron. Preliminary Paper. 



By Theodore William Richards and Gregory Paul 

 Baxter 251 



XIV. On Certain Colored Substances Derived from. Nitro Compounds. 



Third Paper. By C. Loring Jackson and F. H. Gazzolo 261 



XV. The Metamei-ism of the Hirudinea. By W. E. Castle . . . 283 



XVI. 1. New Species and Varieties of Mexican Plants. By J. M. 

 Greenman. 



2. Synopses of the Genera Jaegeria and Russelia. By B. L. 



Robinson. 



3. New Dioscoreas from Mexico. By E. B. Uline. 



4. New Phaenogams, chiefly Gamopetalae, from Mexico and 



Central America. By B. L. Robinson 305 



XVII. The Freshwater Tertiary Formations of the Rocky Mountain 



Region. By W. M. Davis 343 



XVIII. On the Determination of Sulphuric Acid in the Presence of Iron ; 

 a Note on Solid Solutions. By Theodore William 

 Richards 375 



XIX. The Species of the Orthopteran genus Derolmema. By Samuel 



II. SCUDDER 385 



XX. Vieio of the Carboniferous Fauna of the Narraganselt Basin. 



By Alpheus S. Packard 397 



XXI. Preliminary Diagnoses of New Species of Laboulbeniaceae. — //. 



By Roland Thaxter 407 



XXII. Historical Notes relating to Musical Pitch in the United States. 



By Charles R. Cross 451 



XXIII. The Driving Energy of Physico- Chemical Reaction, and its 



Temperature Coefficient. By Theodore William Richards 469 



XXIV. Supjilementary Note on the Chief Theorem of Lie's Theory of 



Finite Continuous Groups. By Stephen Elmer Slocum . 481 



